JPH10283939A - Front panel for plasma display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a front panel for a plasma display, protecting the image display glass substrate of the plasma display and having selective wavelength absorptivity, an external light antireflection property, and an electromagnetic wave blocking property, which enhance picture quality. SOLUTION: This front panel has a transparent conductive film 5 having a glareproofing film 3 on at least one side of a transparent resin sheet 4 and a conductive layer on the other side, with the transparent resin sheet 4 having selective wavelength absorptivity satisfying at least one of the requirements shown as (1)-(3) below, and has an earth electrode 7 on at least a portion of the conductive layer: (1) a spectral transmission factor in the visible wavelength range is 60-90% at 440-470 nm, 5085% at 520-550 nm, and 50-93% at 600-630 nm; (2) a spectral transmission factor at 800-900 nm in the near infrared wavelength range is 65% or less; (3) a spectral transmission factor at 950 nm in the near infrared wavelength range is 65% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front panel for a plasma display which protects a glass substrate of the plasma display and can be suitably used on the front of an image display panel.

[0002]

2. Description of the Related Art In recent years, in the field of video equipment represented by color television, there is a high demand in the market for high definition and large screen of projected images. The light-emitting panel system using a plasma display is being developed as a leading device of a wall-mounted television for high-definition television, because of its features such as light weight and the largest size, high-speed response, wide viewing angle, and color reproducibility.

[0003] In a plasma display, a phosphor is made to emit light by glow discharge in a glass substrate, and this emission is directly observed. In the plasma display panel, a screen-shaped transparent panel is provided as a protective plate on the front surface of a glass substrate.

[0004] The plasma display ranges from the ultraviolet wavelength region to the non-ionizing radiation region of the infrared, microwave, and radio wave regions depending on the structural factors of the light source serving as an image signal source and the discharge portion or each pixel constituting the image. Light rays and wavelengths outside the visible light wavelength range of the three primary colors (red, green, and blue) of a color image are radiated, which causes problems such as flickering of the screen, uneven color tone, and electromagnetic wave radiation.

[0005] If these problems are to be solved by adjusting the electric signals on the drive circuit of the device, secondary problems such as a decrease in overall luminance of the screen and a decrease in color resolution occur.

Accordingly, light loss due to light scattering and diffusion is small, the amount of light in the red, green, and blue wavelength ranges is controlled to enhance color gradation, an anti-reflection function for external light, and absorption of near infrared rays. Further, a panel that shields harmful electromagnetic waves is desired.

For example, in order to enhance the white balance of brightness and the gradation of color, there is a demand for a selective wavelength absorption panel in the visible light region in which the amount of light in the red, green, and blue wavelength regions is controlled.

The wavelengths are 820 nm, 880 nm, 98
Strong near-infrared radiation is measured around 0 nm and the like. It has been pointed out that this near-infrared radiation causes problems such as malfunctions in peripheral devices. This is because, for example, the operating wavelength of a near-infrared communication device such as a remote controller of a television, a video or a cooler, a portable communication device, a personal computer, or the like is matched.

There are many proposals for optical filters for absorbing near-infrared rays, such as sunglasses or goggles, which control plant growth and protect eyes from flashes and heat rays in sunlight, arc welding and the like. For example, JP-A-54-25060 discloses a plastic film that absorbs near infrared rays, JP-A-57-198413,
JP-A-61-1704, JP-A-62-1873
JP-A-7-10 / 1999 discloses an optical filter in which a benzenedithiol-based metal complex is blended with a thermoplastic resin.
No. 0996 discloses a near-infrared absorbing film in which an organic near-infrared absorbing layer is formed on a transparent film surface and an inorganic near-infrared absorbing layer is formed thereon.

However, these near-infrared absorbing filters have not been proposed as a front panel of a video device, and when used as a front panel of a video device, have a low total light transmittance or a spectral light beam over the entire visible light wavelength range. There is a problem with transmittance. In addition, even if there is a compound having a high spectral light transmittance in the visible light wavelength region and a good near-infrared absorption region, there are many compounds that are unstable in heat stability, and can be well blended with the resin of the front panel. Have difficulty.

On the other hand, in the plasma display panel, a transparent resin panel or the like is used on the front surface of the image display screen section for the purpose of protecting the glass substrate, but external light such as an indoor lamp, a fluorescent lamp or sunlight is used. There is a need for improved anti-reflection of external light since the video and image reflected on the panel surface in the direction of the observer and the reproduced image and image become difficult for the observer to see.

As a method of preventing external light reflection,
A method of forming a multilayer deposited film utilizing irregular reflection of light and interference of light has been proposed. For example, Japanese Unexamined Patent Publication No. Hei.
Japanese Patent Application Publication No. 37-307 discloses a method of forming an antireflection film directly on the panel surface by coating or the like using silicon dioxide or the like, whose average particles are ultrafine particles having a wavelength equal to or less than the wavelength of visible light.
No. 104 and JP-A-8-144048 disclose an antireflection film in which a cured film is formed on the upper surface of a transparent plastic film, an aluminum oxide layer is formed thereon by a sputtering method, and a magnesium fluoride layer is formed by a vapor deposition method. Laminated filter, JP-A-6-160982, JP-A-7-160982
JP-168003, JP-A-7-28169,
Japanese Patent Application Laid-Open No. 8-48935 discloses a method of forming a low refractive index layer on a resin substrate, and the like.

In recent years, there has been increasing interest in electromagnetic waves emitted from display monitors. In conventional direct-view CRT televisions, the housing was considerably larger than the image output surface, and the circuit could shield electromagnetic waves because of a separate substrate.However, in plasma displays, the substrate was a glass substrate and the overall thickness of the housing was thin and compact. Since the housing is designed, the area ratio of the emission surface of the entire housing is large, so that only the inside of the housing is subjected to the conductive treatment, it is not possible to sufficiently shield electromagnetic waves, and electromagnetic waves leak from the light emission surface. Further, the regulations of VCCI (Self-Regulation Council for Electromagnetic Disturbance such as Information Processing Equipment) are becoming stricter year by year, and strict electromagnetic wave shielding measures are required.

As electromagnetic wave shielding techniques, there are many proposals for various electromagnetic wave shielding materials in which a transparent conductive layer made of an oxide thin film is formed on a transparent plastic substrate. For example, JP-A-63-173395, JP-A-2-21149
No. 3, JP-A-5-323101, Japanese Patent Publication No. Hei 4-323101.
No. 5,161, Japanese Patent Publication No. 7-89597, and the like are disclosed.

However, no proposal has been made for a front panel or the like which simultaneously has the functions of absorbing selected wavelengths, absorbing near-infrared rays, preventing external light reflection, and shielding electromagnetic waves.

[0016]

SUMMARY OF THE INVENTION An object of the present invention is to provide a front panel of a plasma display substrate, in which, besides protecting the internal structure of the plasma display, in order to obtain a preferable color image, light loss due to light scattering and diffusion is reduced. ,
Red, green, and blue wavelength bands or / and 800-950
controlling the transmission in the wavelength range of
It has a function to efficiently transmit light in the visible light wavelength range of 0 nm, and a function to prevent malfunctions to peripheral devices due to near-infrared rays emitted from the image display surface of the board, as well as to prevent external light reflection. And to provide a panel that shields harmful electromagnetic waves.

[0017]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a compound having a light absorption property in a specific wavelength region of a light source or a light source serving as an image signal source is emitted from a discharge portion. A selective wavelength-absorbing transparent resin sheet that satisfies the required optical properties is obtained by compounding and dispersing in a transparent resin, and an antiglare-treated film on one surface of the transparent resin sheet and a transparent conductive film on the other surface. It has been found that the above-mentioned object is achieved by stacking.

That is, the present invention provides a transparent resin sheet having an antiglare treatment film on at least one surface and a transparent conductive film having a conductive layer on the other surface, wherein the transparent resin sheet has a total light transmittance of 60 to 85. %, And a panel having a selected wavelength absorptivity satisfying at least one of the following conditions (1) to (3), wherein at least a part of the conductive layer has a ground electrode: It is a display front panel.

(1) Spectral transmittance in the visible light wavelength range is 440
60-90% at ~ 470 nm, 5 at 520-550 nm
0 to 85%, 50 to 93% at 600 to 630 nm (2) 800 to 900 nm in the near infrared wavelength region
(3) Spectral transmittance at 950 nm in the near infrared wavelength region is 65% or less.

A more preferable front panel for a plasma display can be obtained by laminating and laminating an anti-glare treatment film and a transparent conductive film on a transparent resin sheet via an adhesive layer.

Further, when the spectral transmittance of at least one of the anti-glare treatment film and the transparent conductive film in the near infrared wavelength region of 950 nm is 65% or less, a more preferable front panel for a plasma display can be obtained.

Further, the antiglare treatment film has a more preferable front panel for a plasma display by having an antistatic layer and an antireflection layer made of a low refractive index fluororesin on one surface of a transparent resin film substrate. can get.

[0023] Further, the transparent conductive film has a transparent conductive layer having a surface resistance value of 30 Ω / □ or less, comprising a noble metal thin film layer on one surface of a transparent resin film substrate, so that the front surface for a plasma display is more preferable. A panel is obtained.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of a representative configuration example showing a state in which a front panel for a plasma display of the present invention is mounted on a plasma display. FIG. FIG.

In the figure, 1 is a glass substrate of a plasma display main body, 2 is a ground portion such as a conductive chassis and a ground electrode, 3 is an anti-glare film, 4 is a transparent resin sheet, 5
Is a transparent conductive film, and the anti-glare processing film 3 has a conductive layer so that the anti-glare processing surface faces the image generation surface, that is, the direction opposite to the glass substrate 1 surface of the plasma display body. The surface is arranged so as to face the image generation surface or a direction opposite to the image generation surface. An earth electrode 7 is formed at least in part on the conductive layer of the transparent conductive film 5 for shielding electromagnetic waves, and an earth wire 8 is drawn from the earth electrode 7 and connected to the earth part 2.

The exposed portion of the conductive layer may be guarded or masked, and a transparent protective film 6 may be further laminated thereon to protect the conductive layer if necessary.

The transparent resin sheet 4 used in the present invention is required to have a small loss of light amount due to scattering and diffusion of light, and has a haze of 1 measured according to JIS K-7105.
It is defined as a resin sheet of 0% or less.

Specific examples include sheets of methacrylic resin, polycarbonate resin, polystyrene resin, styrene-butadiene resin, polyvinyl chloride resin and the like. Particularly preferred is a methacrylic resin sheet.

The methacrylic resin is a resin mainly composed of methyl methacrylate, and is a homopolymer, or methyl methacrylate and methyl acrylate, ethyl acrylate, n-
Propyl acrylate, isopropyl acrylate, butyl acrylate, acrylonitrile, acrylic acid, methacrylic acid, vinyl pyridine, vinyl morpholine, vinyl pyridone tetrahydrofurfuryl acrylate, N,
Any one of copolymerizable monomers such as N-dimethylaminoethyl acrylate, N, N-dimethylacrylamide, 2-hydroxyacrylate, ethylene glycol monoacrylate, glycerin monoacrylate, maleic anhydride, styrene or α-methylstyrene The above-mentioned copolymer, a heat-resistant acrylic resin, a low-moisture-absorbing acrylic resin, and the like are included, and they may be used alone or in a blend.

In order to maintain transparency and simultaneously provide impact resistance, an impact-resistant acrylic resin is used, and its rubber elastic body is disclosed in JP-A-53-55854 and JP-A-55-94.
Nos. 917 and 61-32346. Briefly, it is a multi-stage polymer produced by a multi-stage sequential polymerization method in which an elastic layer and an inelastic layer are alternately formed around an acrylic polymer core material.

The transparent resin sheet 4 used in the present invention has a total light transmittance of 60 to 85% and a selected wavelength absorption satisfying at least one of the following conditions (1) to (3). Has the property.

(1) The spectral transmittance in the visible light wavelength range is 440.
60-90% at ~ 470 nm, 5 at 520-550 nm
0 to 85%, 50 to 93% at 600 to 630 nm (2) 800 to 900 nm in the near infrared wavelength region
(3) Spectral transmittance at 950 nm in the near infrared wavelength region is 65% or less.

It is preferable that the total light transmittance is 60 to 85% because the original luminance of the plasma display is not greatly reduced. Further, a total light transmittance of 70% or more is most preferable. In the present invention, the total light transmittance was measured by measuring the resin composition constituting the transparent resin sheet 4 with 0.1%.
The sheet is formed into a sheet having a thickness of 5 to 10 mm, more preferably 1 to 5 mm, and the measurement is performed using a commercially available measuring instrument according to JIS K-7105.

By satisfying the condition (1), the color balance of a color image can be easily maintained, and the external light contrast can be improved by absorbing external light rays. That is, the light intensity of the fluorescent luminous body differs depending on the type and model of the plasma display image device, and it is necessary to arbitrarily control the light transmittance in the red, green, and blue wavelength bands, which are the three primary colors of a color image. In particular, in the case of the DC type plasma display model, the fluorescent light emitting pixel structure has a quartet structure and there are many red, green and blue green light emitting pixels of the three primary colors, so that the blue light intensity is emphasized in order to obtain a white balance. It is necessary to suppress the transmittance of green light with high light intensity without lowering the light transmittance, and the difference in absorbance between blue and green is 0.02 to 0.20.
What is desired is. Preferably, 0.05 to
It is desirable to have an absorbance difference of 0.15. In this case, if the transmittance in the green wavelength band is simply reduced, the panel color becomes reddish, and the sense of unity with the housing of the video device is impaired. In this case, it is preferable to absorb a long wavelength region of 650 nm or more.

By satisfying the above condition (2) and / or (3), it is possible to absorb near-infrared rays emitted from the plasma display video device and prevent malfunction due to electromagnetic wave radiation to peripheral devices. Preferably 20%
Or less, more preferably 10% or less. 5% or less is most preferable for preventing malfunctions to the infrared communication device such as a remote control and a personal computer.

The selective wavelength absorption of the transparent resin sheet 4 can be obtained by mixing and dispersing a selective wavelength absorbing compound having an absorption characteristic in a specific wavelength range in the transparent resin.

The selective wavelength absorbing compound is 400 to 1000
It is selected from those having an absorbance of 0.01 or more in the wavelength region of nm and is used. The resin is uniformly dispersed in a transparent resin, and the optical properties of the resin composition are uniform at 25 ° C. It is preferable that the powder is in the form of a powder. Further, since the size of the selected wavelength absorbing compound powder also affects the optical properties of the composition, the weight average particle size of the powder is 0.01 to 50 μm.
It is preferably within the range of m.

Specific examples include light absorbing compounds such as inorganic pigments, organic pigments and dyes, and near infrared absorbing compounds such as near infrared absorbing dyes.

Examples of the inorganic pigments include titanium dioxide, sulfur-containing sodium aluminosilicate pigment, iron ferrocyanide, ferric ferrocyanide, cobalt aluminate, chromium oxide, hydrated chromium oxide, lead chromate, and basic chromium. Lead oxide, lead sulfate, lead molybdate, cadmium sulfide, cadmium selenide, cadmium carbonate, iron oxide, ferric oxide, cuprous oxide, basic zinc potassium chromate, strontium chromate pigments, carbon black, etc. Can be

Examples of the organic pigments include azo lake pigments, insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, copper phthalocyanine, quinacridone pigments, isoindolinone pigments, and bat pigments (anthrapyrimidine, flavanthrone, brominated anthanthrone, perinone). , Perylene, thioindigo, chlorinated isobiolanthrone, indanthrone, oxazine, alizarin) and the like.

Examples of the dye include azo dyes, bisazo dyes, trisazo dyes, anthraquinone dyes, triphenylmethane dyes, polymethine dyes, indigoid dyes, quinophthalone dyes, azochrome complex salt dyes, stilbene dyes, and pyrazolones. Dyes and naphthazine dyes.

Examples of near-infrared absorbing dyes include cyanine dyes, azurenium dyes, squarium dyes, croconium dyes, triphenylmethane dyes, oxazine dyes, azine dyes, trisazotriphenylamine dyes, naphthoquinones Dyes, naphthalocyanine metal complex dyes, indoaniline metal complex dyes, dithiol
Examples include metal complex dyes and diiminium compounds.

These selective wavelength light absorbing compounds may be used alone or in combination of two or more.

Preferred selective wavelength absorbing compounds include organic colorants such as purple, red, green and yellow dyes and organic pigments.

It is most effective when an organic pigment is used in combination with a dithiol / metal complex pigment or a diiminium pigment which is a near infrared absorbing pigment.

The dithiol / metal complex dye has a very low light absorption in the visible light region, absorbs an ultraviolet region, and has a very large absorbance at a maximum absorption wavelength in the near infrared region. Has high luminous transmittance. Further, the dithiol / metal complex dye is a compound which has good thermal stability, does not have hygroscopicity, is extremely stable even when brought into contact with water, and can be easily incorporated into a transparent resin.

Specific examples include dithiol / metal complex dyes represented by the following general formula (1).

[0049]

Embedded image

(Wherein, R1 to R4 represent the same or different phenol groups or naphthyl groups, and represent hydrogen, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, a phenoxy group, a hydroxy group, an alkylamino group,
One to three, the same or different, may be substituted by an arylamino group, a trifluoromethyl group, an alkylthio group, an arylthio group, a nitro group, a cyano group or a halogen atom. M is any one of nickel, platinum and palladium. )

Such dithiol / metal complex dyes are described, for example, by Harry Bee Gray and others in Journal of the American Chemical Society (JAA.
C. S, 88, 4870-4875, 1966)
According to the method disclosed in (1), dithiols are reacted with nickel chloride, and then this reaction solution is reacted with a quaternary ammonium halide. As the quaternary ammonium group, tetra-n
-Butylammonium group, tetra-n-propylammonium group, trioctylmethylammonium group and the like are used.

The diiminium-based dyes include dyes represented by the following general formula (2).

[0053]

Embedded image

Wherein R5 to R12 are the same or different hydrogen, alkyl, aryl, alkoxy, phenoxy and hydroxy groups, and X ^- is a halogen anion, a perchlorate anion or a hexafluoride. Anion represented by antimonate anion and nitrate anion.)

The diiminium dye is not particularly restricted but includes, for example, IRA-022 manufactured by Kyodo Yakuhin, CIR-1080 manufactured by Nippon Carlit and IRG-0 manufactured by Nippon Kayaku.
Commercially available products such as No. 22 can be suitably used. Among them,
In the formula (2), a dye in which R5 to R12 are n-butane is particularly preferable.

This diiminium dye has a maximum absorption wavelength in the near infrared region at 940 to 1100 nm. As a front panel for a plasma display, a dithiol / metal complex-based dye and a diiminium-based dye are required since they transmit the visible light wavelength range of 400 to 700 nm and have near-infrared absorption characteristics in a wide range of 800 to 1000 nm. It is the most preferable to use them in combination.

The amount of the selected wavelength absorbing compound is greatly related to the thickness of the transparent resin sheet 4. Therefore, the transmittance is
Lambert-Beer has a correlation with the product of the weight concentration of the selected wavelength absorbing compound and the thickness of the transparent resin sheet 4.
From the law, the following equation is generally known.

-Log (T / t) = E.times.C.times.B [T: transmittance of the transparent resin when the selected wavelength absorbing compound is added, t: transmittance of the transparent resin alone, E: extinction coefficient of the transparent resin (Constant), C: weight concentration of selected wavelength absorbing compound, B: thickness of transparent resin sheet]

That is, the transmittance is governed by the product of the weight concentration and the thickness. This unit is expressed in wt% · mm. This means that when the weight density per unit area is important and the transmittance is constant, this is called the area density. For example, when the concentration of the selected wavelength absorbing compound is 1 wt%, the thickness of the transparent resin sheet is 5 mm and the concentration is 0.5 wt%, and when the thickness of the transparent resin sheet is 10 mm, the area concentration is 5 wt% · mm. The transmittances are equal.

The preferred area concentration of the selected wavelength absorbing compound is 0.001 to 0.3 wt% · mm. Within this range, the absorption amount in the visible light wavelength region and / or the near-infrared absorption amount is sufficient, and the total light transmittance is preferably high.

The thickness of the transparent resin sheet 4 is 1.0 to 20
mm is preferred. In particular, 2.0 to 10 mm is the most preferable thickness. When the thickness of the transparent resin sheet 4 is 1.0 mm or more, rigidity as a front panel is obtained, and
mm or less is preferable because it is lightweight as a front panel.

The method of forming the transparent resin sheet 4 is not particularly limited, but can be easily obtained by using, for example, an extruded sheet forming method using a T-die. The sheet may be subjected to secondary processing by vacuum forming, pressure forming, or stampable forming.

Further, other components such as a reinforcing agent, a filler, and the like may be used as long as the optical characteristics and the mechanical and thermal characteristics are not impaired.
A release agent, a heat stabilizer, an antioxidant, a nucleating agent, a light stabilizer, an ultraviolet absorber, a plasticizer, and the like can be contained in any process such as production of a selective wavelength absorbing resin composition or sheet molding. it can.

The anti-glare film 3 used in the present invention
Is obtained by using a transparent resin film as a base material and subjecting one surface thereof to an antiglare treatment.

The transparent resin film substrate is preferably such that light loss due to light scattering or diffusion is small and the refractive index is large, and polyethylene terephthalate (refractive index: 1.65), which is generally easily available, is used. Polyester, polycarbonate (refractive index: 1.58), triacetyl cellulose (refractive index: 1.52), polymethyl methacrylate (refractive index: 1.49), polystyrene (refractive index: 1.6)
0), polyvinyl chloride (refractive index: 1.53) and the like are preferably mentioned as suitable examples.

The thickness of the transparent resin film substrate is 25 to 2
00 μm is preferred. In particular, 50 to 150 μm is the most preferable thickness. The thickness of the transparent resin film substrate is 25
If the thickness is at least μm, the strength will be sufficient, and if it is at most 200 μm, the rigidity of the film will be high and there is no problem that the secondary workability on the surface of the transparent resin sheet 4 will be inferior.

There is no particular limitation on the antiglare treatment, and any processing method can be selected. For example, a method of reducing luminous reflectance by irregularly reflecting external light, that is, applying light to a surface of the transparent resin film substrate by applying silicon dioxide or the like, which is an ultrafine particle having a particle size equal to or smaller than the wavelength of visible light, on one surface of the transparent resin film substrate. A method of forming an antireflection film in which irregular reflection of light is generated, or a method of forming a cured film on one surface of a transparent resin film substrate and forming a magnesium fluoride layer thereon to form an antireflection layer by a vapor deposition method, or transparent. A method of forming a thin low refractive index layer on one or both sides of a resin film substrate is known,
These can be used as appropriate.

Among them, a simple and effective method is to form a thin refractive index layer and reduce the reflectance by the interference between the light reflected on the surface of the low refractive index layer and the light reflected and refracted at the interface. That is, when an antireflection layer having a lower refractive index than the transparent resin film substrate is formed as the outermost layer with a film thickness of 1/4 of the wavelength of visible light, the upper surface reflected light and the lower surface reflected light cancel each other out, so that the surface reflection occurs. Can be reduced.

The refractive index of the antireflection layer is preferably lower than the refractive index of the transparent resin film substrate, and the total light reflectance is preferably less than 7%. The low-refractive-index transparent resin forming the anti-reflection layer is not particularly limited, but is most preferably an amorphous transparent fluorinated polymer, and has a refractive index of 1.28 to 1.44. Is more preferred.

Examples of such a noncrystalline transparent fluoropolymer include perfluorooctane, CF ₃ (C
F ₂ ) nCH = CH ₂ (n: 5 to 11), CF ₃ (CF ₂ )
Polymers soluble in a specific fluorine-based solvent such as mCH ₂ CH ₃ (m: 5 to 11), a fluorinated alkyl ester polymer of acrylic acid or a fluorinated alkyl ester polymer of methacrylic acid, trade name “CYTOP” ( Asahi Glass Co., Ltd.), trade name "Teflon AF" (DuPont) and the like.

Another preferred anti-glare treatment is disclosed in
And a method disclosed in JP-A-122501.
That is, a silica sol having a particle diameter of 5 to 30 nm (a)
And at least one component (b) selected from the group consisting of a hydrolyzate of an alkoxysilane, a hydrolyzate of a metal alkoxide and a metal salt, and (a) SiO ₂
(B) is converted to a metal oxide with respect to 100 parts by weight,
A coating solution contained in an organic solvent in a ratio of 0 to 50 parts by weight,
This is a method of forming an antireflection layer by applying the composition to a substrate and then curing the composition. The antireflection layer formed by this method has an external light reflectance of 5%.
Is preferable, and the external light reflectance is more preferably less than 2%.

Commercially available anti-reflection transparent resin films include “Arc Top” (trade name) (manufactured by Asahi Glass Co., Ltd.) and “Real-Look” (trade name) (manufactured by NOF Corporation).

The thickness of the antireflection layer is 0.05 to 0.25
The range of μm is preferable because the antireflection performance is sufficient. In order to reduce reflection in the visible light wavelength range when observing an image screen, it is more preferable that the total light reflectance is less than 5% at a thickness of 0.1 to 0.2 μm.

The antireflection layer is coated on a transparent resin film substrate by a spray coating method, a spin coating method, a dip coating method, a roll coating method, a gravure coating method, a die coating method or the like. These coating methods can be continuously processed, and are superior in productivity as compared with a batch type evaporation method or the like. In order to enhance the adhesion of the antireflection layer to the transparent resin film substrate surface, an active energy ray treatment such as a corona discharge treatment or an ultraviolet treatment, or a primer treatment may be applied.

Further, it is more suitable for a panel to have an antistatic layer between the transparent resin film substrate and the antiglare treatment layer. The antistatic agent is preferably coated with a metal oxide such as tin oxide, a surfactant, or a transparent conductive layer, and has a surface resistance of 10 ¹⁰ Ω or less.

The transparent conductive film 5 used in the present invention
Is based on a transparent resin film and has a conductive layer on one surface thereof. In particular, light loss due to scattering and diffusion of light in a visible light wavelength region is small, and light transmittance at 550 nm is 70% or more. It is desirable that Also,
It is preferable that the electromagnetic wave attenuation effect at a frequency of 100 MHz is 50% or more.

The transparent resin film substrate is generally made of polyester such as polyethylene terephthalate, which is easily available.
Suitable examples include polycarbonate, triacetyl cellulose, and polymethyl methacrylate.

The thickness of the transparent resin film substrate is 25 to 2
00 μm is preferred. In particular, 50 to 100 μm is the most preferable thickness. The thickness of the transparent resin film substrate is 25
If it is at least μm, the strength is sufficient, and if it is at most 200 μm, the rigidity of the film will be high and the secondary workability on the surface of the transparent resin sheet 4 will not be inferior.

Examples of the conductive layer include a metal layer such as a noble metal thin film layer. Examples of the noble metal forming the noble metal thin film layer include gold, silver, palladium, and alloys thereof, and are preferably silver and an alloy of silver and gold. In the case of an alloy, the silver content is preferably 60% by weight or more. The surface resistance of the conductive layer is preferably 30 Ω / □ or less, more preferably 15 Ω / □ or less.

It is preferable to laminate a transparent dielectric layer in order to reinforce the metal layer, protect it, prevent oxidative deterioration, and increase the transmittance in the visible light region. Examples of the transparent dielectric layer include thin films of oxides of divalent to tetravalent metals, zirconium oxide, titanium oxide, magnesium oxide, silicon oxide, aluminum oxide, and metal alkoxide compounds. When the transparent dielectric layer is provided on both the surface side and the substrate side of the metal layer, both may be the same substance or may be different.

Further, in order to protect the conductive layer, a transparent protective film 6 is preferably laminated.

The transparent protective film 6 is, for example, a polyethylene film or polyester. Transparent films of polycarbonate and triacetyl cellulose are exemplified. Further, the above-described antiglare film may be used as the transparent protective film 6.

The structure of the conductive layer is, for example, when the transparent resin film substrate is (A), the metal layer is (B), the transparent dielectric layer is (C), and the transparent protective film 6 is (D). ,
(A) / (B) / (C) / (B) or (A) / (B)
It is particularly preferable that the metal layer (B) and the transparent dielectric layer (C) are further laminated in multiple layers in the order of / (C) / (B) / (D).

The thickness of the metal layer is preferably 50 to 300 Å. If it is 50 Å or more, the electromagnetic wave shielding effect is sufficient. When the thickness is 300 Å or less, the light transmittance can be 70% or more, which is preferable.

The thickness of the transparent dielectric layer is 200 to 3000
Angstrom is preferred. Within this range, a high transmittance can be obtained in the visible light range, which is preferable. Preferably, 40
0 to 1000 angstroms.

The method for forming the metal layer and the transparent dielectric film layer is not particularly limited, and an arbitrary processing method can be selected. For example, electron beam evaporation, vacuum evaporation,
Any conventionally known method such as a cathode sputtering method and an ion plating method can be used.

The front panel of the present invention needs to be grounded to shield electromagnetic waves. This is a transparent conductive film 5
By providing an earth electrode 7 on at least a part of the conductive layer of
What is necessary is just to connect directly to the earth part 2 of a plasma display main body housing.

The ground electrode 7 may be formed on the periphery of the panel and a part or all of the portion covered by the outer frame cover of the plasma display so as not to disturb the display of images and characters from the plasma display. Preferably, the surface is grounded.

The method for forming the ground electrode 7 is not particularly limited, and for example, a method of forming a conductive silver paste as a main component by a printing method, a method of attaching a copper tape, and the like are appropriately applied.

Further, the ground wire 8 is connected to the main body conductive chassis,
By connecting and fixing to the main body grounding portion 2 such as a ground electrode, electromagnetic wave shielding can be effectively exhibited. It is also preferable to use metal packing in this connection.

The method of laminating the anti-glare treatment film 3 and the transparent conductive film 5 used in the present invention on the transparent resin sheet 4 is not particularly limited. A method is preferable in which the antiglare-treated surface of the material or the surface opposite to the conductive layer surface is bonded and laminated to the transparent resin sheet 4 via an adhesive layer. There is no particular limitation on the method of laminating to the transparent resin sheet surface, and a method such as visco-compression bonding or heat fusion is appropriately selected.

The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited, and those usually used for pressure-sensitive adhesive sheets and films can be suitably used. Above all, acrylates using polybutyl acrylate, 2-ethylhexyl polyacrylate, polyisobutylene-based, and SBR, which are transparent and have a glass transition temperature of the main component resin in the range of −50 ° C. to −130 ° C. System, rubber system such as natural rubber, urethane
Acrylate, epoxy-acrylate, silicone rubber, vinyl chloride or vinyl acetate content of 20
~ 40% ethylene vinyl acetate is preferred.

Examples of the tackifier include rosin, rosin ester and its derivatives, terpene resin, phenol resin,
Coumarone-indene resin, hydrocarbon resin, etc. are used,
Further, fatty acid esters, animal and vegetable fats and oils, waxes, and heavy petroleum fractions are used as softeners, and are appropriately selected based on their compatibility with the transparent main component resin.

The thickness of the pressure-sensitive adhesive layer is preferably in the range of 5 to 200 μm because of high transparency. When the thickness of the adhesive layer is 5 μm or more, it is easy to form the adhesive layer uniformly,
When the thickness is not more than μm, for example, it is preferable because there is no problem that defects such as wrinkles easily occur during lamination and integration on a display panel surface or the like under a high temperature in summer. A more preferred thickness of the adhesive layer is 10 to 50 μm.

The pressure-sensitive adhesive layer is formed by applying the above-mentioned pressure-sensitive adhesive by a commonly used coating method such as transfer printing, a knife coater, a roll coater, or a gravure coater, and dried by heating with infrared rays, hot air, steam, or the like. On one side.

The anti-glare effect is obtained by, for example, adding the above-mentioned selective wavelength absorbing agent used for the transparent resin sheet 4 to the adhesive layer, or forming a layer containing the selective wavelength absorbing compound on the surface of the adhesive layer by a printing method or the like. The treatment film 3 and / or the transparent conductive film 5 may have a selected wavelength absorption. The compounding amount of the selected wavelength absorbing compound is determined by the amount of the transparent resin sheet 4
Is the same as

In particular, a near-infrared absorbing compound having inferior heat stability is compounded in an adhesive layer and is used by attaching it as a near-infrared absorbing sheet, or is mixed with an acrylic printing ink material and printed on the adhesive layer. Is a more preferred method. Examples of the near-infrared absorbing compound include the above-mentioned compounds used for the transparent resin sheet 4, and among them, dithiol / metal complex dyes and diiminium dyes are preferable. In this case, the transmittance of the antiglare film 3 or the transparent conductive film 5 in the near infrared wavelength region at 950 nm is preferably 65% or less.

The shape of the panel and the method of forming the panel are not particularly limited. For example, if an extruded sheet forming method using a T-die is used, a smooth, corrugated, prism-shaped sheet-shaped panel formed body can be obtained. The sheet-shaped panel molded body may be subjected to secondary processing by vacuum forming and pressure forming. When the panel shape of the video equipment is complicated, a molded article having a desired shape can be obtained by irregular extrusion molding, blow molding, injection molding, compression molding, or the like using an annular die.

Further, in order to obtain a panel having a multilayer structure, a coextrusion molding method in which two or more resin compositions are simultaneously melt-extruded, and one of the two resin compositions is molded in advance while extruding a single layer. There are a method of laminating the other, a method of forming two kinds of resin compositions in advance and pressing and thermocompression bonding, a method of continuously overlapping and bonding, a method of laminating at the time of vacuum forming and pressure forming, and the like.

A preferred method is to use the transparent resin sheet 4
Is extruded into a sheet shape using a T-die, the anti-glare treatment film 3 is formed on one side, the transparent conductive film 5 is formed on the other side, and the temperature of the transparent resin sheet 4 before lamination is 20.
~ 90 ° C and tension of the film is 1-10kg
/ M (per roll length) continuously under tension
This is a method of laminating at a roll pressure of 0.5 to 4 ton / m, which is advantageous because it can be uniformly laminated and pressure-bonded with little distortion. According to this method, continuous production is easy, the process is simple, and mass productivity is excellent, which is preferable. Further, it is preferable to use an expander roll or a spiral roll as the tension roll because it is possible to prevent wrinkles of the film during lamination.

The temperature of the transparent resin sheet 4 before lamination is 20 ° C.
If it is more than the above, lamination unevenness is hardly generated and the film is hardly peeled off, which is preferable. If the temperature of the transparent resin sheet 4 before lamination is 90 ° C. or less, it is preferable because there is no problem that the temperature is too high and a problem occurs in the polyethylene-based protective film. The temperature of the transparent resin sheet 4 at the time of lamination is most preferably 30 to 70 ° C. because the lamination adhesive strength is high.

If the tension at the time of laminating the anti-glare treatment film 3 and the transparent conductive film 5 is 1 kg / m or more, there is no problem that the polyethylene-based protective film is not smoothly removed and the tension is uneven. preferable. Further, when the tension is 10 kg / m or less, there is no problem that the tensile stress of the film remains and causes the warpage of the panel, which is preferable.

When the roll pressure is 0.5 ton / m or more, it is difficult to entrain air, and when the roll pressure is 4 ton / m or less, optical distortion does not occur, which is preferable.

[0104]

The present invention will be described in more detail with reference to the following examples.

The measurement, evaluation and test methods used in each of the examples and comparative examples are as follows.

(1) Total light transmittance: JIS K-710
The measurement is performed using a 1001-DP type haze meter manufactured by Nippon Denshoku Industries Co.

(2) Spectral transmittance: 400 to 110 using a self-recording spectrophotometer (model 330) manufactured by Hitachi, Ltd.
A transmission spectrum is measured in a wavelength range of 0 nm, and a spectral transmittance at an arbitrary wavelength is read.

(3) Spectral reflectance: 400 to 700 using a self-recording spectrophotometer (model 330 type) manufactured by Hitachi, Ltd.
The spectral reflectance of 5 ° reflectance was measured in the wavelength range of
The reflectance at 0 nm was defined as the external light reflectance.

(4) Antistatic performance: The test piece was set on a super insulation meter SME-8310 manufactured by Toa Denpa Co., Ltd., and the surface resistance was measured.

(5) Surface resistance value: The resistance value is measured using a digital multimeter 7541 manufactured by Yokogawa Electric Corporation with the terminals separated by 10 cm.

(6) Electromagnetic wave attenuation effect: The electromagnetic wave shielding measurement method (KEC method) by Kansai Electronics Industry Promotion Center
The electromagnetic wave attenuation effect was measured, and the electric field wave attenuation effect (dB) at 100 MHz was compared.

(7) Evaluation of image contrast: Set on the front of a commercially available plasma display (Plasmavision M21, PDS2123 type, manufactured by Fujitsu General Limited),
The contrast of the image was visually determined. ◎ is good,
The symbol Δ indicates that no effect was observed, and the symbol X indicates that it could not be used.

The selected wavelength absorbing compounds shown in Table 1 are as follows. Microlex Red 5B: Anthraquinone-based organic dye (manufactured by Bayer) Microlex Violet 3R: Anthraquinone-based organic dye (manufactured by Bayer) Diamond Resin Green C: Anthraquinone-based organic dye (manufactured by Mitsubishi Chemical Corporation) Diamond Resin Blue H3G: Heterocyclic dye (Mitsubishi Chemical Co., Ltd.) SIR-159: Dithiol / nickel complex dye (Mitsui Toatsu Chemical Co., Ltd.) SIR-130: Dithiol / nickel complex dye (Mitsui Toatsu Chemical Co., Ltd.) SIR-132: dithiol / nickel complex dye (manufactured by Mitsui Toatsu Chemicals, Inc.)

Example 1 A methacrylic resin (trade name: Del Powder 70H, manufactured by Asahi Kasei Kogyo Co., Ltd.) and a compound shown in Table 1 were blended at the concentrations shown in Table 1 (the number of parts based on 100 parts of the resin).
After blending with a Henschel mixer, the mixture is pelletized at a resin temperature of 250 ° C. with a vented extruder of 50 mmφ to obtain a resin composition. The obtained pellet is formed into an extruded sheet using an extruder (screw diameter 50 mmφ, L / D = 32, single axis), a multi-manifold die, and a unit including three polishing rolls, and the clearance of the polishing roll is adjusted. To form a single-layer transparent resin sheet having a thickness of 2 mm and a width of 300 mm.

At the time of extrusion molding of the transparent resin sheet, a raw roll of the antiglare film is prepared on the upper surface of the extruded sheet, and a raw roll of the transparent conductive layer film is prepared on the lower surface. The sheet is continuously supplied with a tension of 2 kg / m via a feeding roll and a tension roll so as to be positioned on the surface of the extruded sheet.
When it was at 0 ° C., it was laminated with a pressure roll.

The anti-glare treatment film has a thickness of 100 μm.
Anti-reflective properties of anti-glare treatment in which triacetyl cellulose is used as a transparent resin film substrate, anti-static treatment is applied, and a fluorine-containing resin anti-reflection layer is formed thereon, and an acrylic adhesive layer is provided on the opposite surface. The film "Nippon Yushi Co., Ltd. product name: Rialuk" was used. As the transparent conductive layer film, polyethylene terephthalate having a thickness of 120 μm was used as a transparent resin film base material, and the surface resistance value was 10Ω / □.
A transparent conductive film "Tefijin Corp .: trade name Reftel WR02" in which a silver vapor-deposited surface containing silver as a main component was used as a conductive layer and an adhesive layer was provided on the opposite surface.

Further, a surface ground was applied to the exposed outer surface of the silver-deposited conductive layer of the transparent conductive film of the laminate by using a conductive silver paste by a printing method to form a surface ground for the plasma display shown in FIG. The front panel was obtained.

The total light transmittance and the spectral transmittance of the transparent resin sheet were measured, and the obtained panel was used as a test piece, and the total light transmittance was measured. The evaluation of (3) to (7) by the test method described above. I do. The results are shown in Table 2, FIG. 3 and FIG.

It is excellent in the selected wavelength absorbing property, external light reflecting property and electromagnetic wave attenuating effect, and is preferable.

Example 2 A front panel molded body for a plasma display was obtained in the same manner as in Example 1 except that the composition of the transparent resin sheet shown in Table 1 was used. The results are shown in Table 2 and FIG.

It is excellent in the selected wavelength absorbing property, external light reflecting property and electromagnetic wave attenuating effect and is preferable.

The spectral light transmittance in the near infrared region of 800 to 900 nm also shows 15% or less.

(Example 3) Continuous long thickness 100 μm
m on one side of a methacrylic resin film, a primer (manufactured by Asahi Glass; trade name: CT-P10) was diluted to 0.5% of component,
It was applied continuously by a gravure coating method, dried, and subjected to a primer treatment.

Next, a non-crystalline transparent fluoropolymer (manufactured by Asahi Glass Co., Ltd .; trade name: CYTOP CTL-102)
A)) is continuously applied by a gravure coating method using a coater having a roll film transport system, dried, a uniform 0.1 μm thin film is laminated, an antireflection layer is formed, and a polyethylene protective film is formed thereon. Was used for masking.

On a surface opposite to the antireflection-treated surface, 2.0 parts of a diiminium-based compound (trade name: IRG-022, manufactured by Nippon Kayaku Co., Ltd.) was dissolved and dispersed in 100 parts of an acrylic acid-based transparent printing ink, followed by a roll coater method. After printing and drying to a thickness of 10 μm over the entire surface, a transparent pressure-sensitive adhesive containing vinyl acetate and an acrylic acid ester copolymer as a main component and prescribing rosin and an antioxidant is applied to a thickness of about 20 μm by a gravure coating method.
And then masked with a 50 μm-thick polyethylene terephthalate film releasable protective film to obtain an antiglare film having near-infrared absorption characteristics (spectral transmittance at 950 nm of 8%). .

The composition of the transparent resin sheet shown in Table 1 was used. The above film was used as an anti-glare treatment film, and the transparent conductive film was a transparent conductive film having a silver deposited layer having a surface resistance of 2Ω / □ as a transparent conductive layer. A front panel molded body for a plasma display was obtained in the same manner as in Example 1 except that the film “Silver deposited film made by Reiko Co., Ltd.” was used. The evaluation results are shown in Table 2 and FIG.

It is excellent in the selected wavelength absorption and the electromagnetic wave attenuation effect and is preferable.

Example 4 A diiminium compound (trade name: IRG022, manufactured by Nippon Kayaku Co., Ltd.) was used in 100 parts of an acrylic transparent printing ink using the antiglare film used in Example 2 having no adhesive layer. 2 parts are dissolved and dispersed, printed to a thickness of 10 μm by a roll coater method, dried, and then a transparent adhesive is laminated to a thickness of about 20 μm by a gravure roll method,
An antiglare film having near infrared absorption characteristics (spectral transmittance at 950 nm of 8%) was prepared.

A molded front panel for a plasma display was obtained in the same manner as in Example 2 except that the above film was used as the antiglare film. Table 2 shows the evaluation results.

It is excellent in the selected wavelength absorption, external light reflectivity and electromagnetic wave attenuation effect and is preferable.

Further, the spectral light transmittance in the near infrared region of 800 to 1100 nm also shows 10% or less.

Comparative Example 1 Evaluation was made using a transparent acrylic resin plate as a front panel for a plasma display. The results are shown in Table 2 and FIG.

It has no selective wavelength absorption, near-infrared absorption, external light reflection prevention and electromagnetic wave attenuation effects, and is unsuitable as a front panel for a plasma display.

Comparative Example 2 A panel molded product was obtained in the same manner as in Example 1 except that the transparent conductive film was not laminated.
Table 2 shows the results.

Although the selective wavelength absorbing property and the anti-reflection property of external light are recognized as effective, they have no electromagnetic wave attenuation effect and are unsuitable as front panels for plasma displays.

[0136]

[Table 1]

[0137]

[Table 2]

[0138]

According to the present invention, there is provided a front panel for a plasma display having both a selected wavelength absorption property, an external light reflection prevention property, and an electromagnetic wave shielding property for protecting an image display glass substrate of a plasma display and improving image quality. Things.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a representative configuration example showing a state where a front panel for a plasma display of the present invention is mounted on a plasma display.

FIG. 2 is a schematic view of the front panel for a plasma display of the present invention as viewed from the glass substrate surface of the plasma display.

FIG. 3 is a graph showing light transmittance characteristics of a transparent resin sheet used in an example.

FIG. 4 is a graph showing an electromagnetic wave attenuation effect of the front panel for a plasma display of Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate of a plasma display main body 2 Earth part 3 Anti-glare treatment film 4 Transparent resin sheet 5 Transparent conductive film 6 Transparent protective film 7 Earth electrode 8 Earth wire

Claims (5)

[Claims] At least one surface of a transparent resin sheet has an anti-glare treatment film and another surface has a transparent conductive film having a conductive layer, and the transparent resin sheet has a total light transmittance of 60 to 60%.
A panel having a selective wavelength absorption that satisfies at least 85% and at least one of the following conditions (1) to (3), wherein at least a part of the conductive layer has a ground electrode. Front panel for plasma display. (1) Spectral transmittance in the visible light wavelength range is 440 to 470 nm
At 60-90%, at 520-550 nm 50-85%,
50 to 93% at 600 to 630 nm (2) 800 to 900 nm in near infrared wavelength region
(3) Spectral transmittance at 950 nm in the near infrared wavelength range is 65% or less 2. The front panel for a plasma display according to claim 1, wherein the anti-glare treatment film and the transparent conductive film are laminated on a transparent resin sheet via an adhesive layer. 3. The front surface for a plasma display according to claim 1, wherein at least one of the anti-glare treatment film and the transparent conductive film has a spectral transmittance of 65% or less in a near infrared wavelength region of 950 nm. panel. 4. The anti-glare treatment film according to claim 1, further comprising an antistatic layer and an antireflection layer made of a fluorine resin having a low refractive index on one surface of the transparent resin film substrate. A front panel for a plasma display as described in the above. 5. The transparent conductive film according to claim 1, wherein the transparent resin film has a transparent conductive layer having a surface resistance of 30 Ω / □ or less on one surface of a transparent resin film substrate. 5. The front panel for a plasma display according to 4.